Malting process utilizing physical impact of kernels



March 23, 1965 D. BEcKoRD ETAL 374909 MALTING PROCESS UTILIZING PHYSICALIMPACT OF KERNELS Filed Feb. 6, 1964 4 Sheets-Sheet 1 March 23, 1965 l..D. BEcKoRD ETAL 3,174,909

MALTING PROCESS UTILIZING PHYSICAL IMPACT OF' KERNELS Filed Feb. 6, 19644 Sheets-Sheet 2 MPN .gmbh b5 .HEMD @Ml m ZQPNTFDI E s. S om E 'w-r/l/wuva/fg s asf waa/ J Afr/3A 003e! March 23, 1965 L. D. BECKORD ETAL3,174,909

MALTING PRoCEss UTILIZING PHYSICAL IMPACT CP KERNELS Filed Feb. 6, 19644 Sheets-Sheet 3 @@@QCCCE @D Q (D Q@ CCD CCD@ @D (D CCD Q@ Q@ @CCD @D 20l l l? le l5 I4 r4 12 n Ausili hl 727m @Way/nga March 23, 1965 l.. D.BEcKoRD ETAL 33749909 MALTING PROCESS UTILIZING PHYSICAL IMPACT OF'KERNELS Filed Feb. 6, 1964 4 Sheets-Sheet 4 W. NUMERICAL VALUES ARE FoaALPH g5 Q7 AMYLASE Acnvlw PER @RAM ROOTLET RECOVE RY-PERCENT |000 zooo5000 Aoco sooo IMPACT ENERGY-9m.cm/KERMEg/aDAYs FQZQZ/ Rom-LET Lossvsfro'rAL IMPc-r wzfenceecm/CZ ENERGY APPuEo PER KERNEL. qyaeygmTHROUGHOUT eenmmmlon United States Patent 3,174,909 MALTING IRCESSUTILIZING PHYSECAL IMPACT F KERNELS Lawrence D. Beckord, Elm Grove, andJohn G. Fleckenstein, Brookeld, Wis., assignors to Kurth MaltingCompany, Miiwaukee, Wis., a corporation of Wisconsin Filed Feb. 6, i964,Ser. No. 343,010 I3 Claims. (Qi. 195-69) This invention relates to maltand processes of producing malt. More particularly, this invention isconcerned with a novel malting process which gives improved recoveries,or yields, of malt by the suppression of the growth or formation ofrootlets by physical means.

This application is a continuation-in-part of our copending applicationSerial No. 113,807, filed May 3l, 1961, and now abandoned.

In the production of malt from barley, the barley kernels are firststeeped by immersing them in water. The steeping continues two to threedays, generally in water at a temperature lof about Sti-65 F. After themoisture content of the barley grains has reached about 35-45%, thesteeping is terminated. This point is generally referred to as steepout.

The next step in the production of malt is the germination of thesteeped barley kernels. In the germination step the steeped grain issubjected to appropriate conditions of temperature, moisture and airsupply for a time suflicient for the interior portion of the barleykernel to be made porous and growth facilitated. This is generallyaccomplished by spreading the barley in beds of various sizes. Growthstarts at the embryo end of the kernel slowly the first day and at anaccelerated rate the second day. The barley kernel begins to chit at thebase of the kernel by showing a white tip. Rootlets then grow outwardlyaway from the tip. The acrospire also starts from the base of the kerneland grows under the hull toward the top end of the kernel. When theacrospire has grown from about 3% length to the full length of thekernel it is generally indicated that the enzymatic system of the barleyhas been fully developed.

After germination has proceeded to the desired extent, the green malt isremoved from the germinating compartments and conveyed to a kiln whereit is dried with heated air. The dried malt is then subsequently cleanedto remove rootlets, loose hulls and broken kernels and then stored.

When the resulting malt is subsequently ground and treated with water atsuitable temperatures, it functions to eiciently convert (a) starches todextrins and sugars, (b) insoluble proteins to soluble proteins duringmashing operations in a brewery or distillery, (c) provide a source ofdesirable taste and aroma which carries through into the finishedproduct, such as beer.

The efficiency of the malting process is evaluated normally by referenceto the number of bushels of malt obtained per bushels of grain that aremalted. Thus, one bushel of barley will usually yield a maximum of about1.18 to 1.20 bushels of malt. If the malting operation was completelyefficient, a yield of about 1.31 to 1.32 bushels of malt would beobtained per bushel of barley. Although more bushels of malt areobtained than bushels of barley started with, it must be noted that onebushel of barley weighs 48 pounds and one bushel of malt weighs 34pounds.

There are two major sources of loss in the conversion of barley to maltduring the germination step. The irst of these is the loss due torespiration during which there is enzymatic conversion of carbohydratein the barley kernel to carbon dioxide and water. Respiration losses areusually in the range from about 5 to 8%. The other loss due togermination is the rootlet loss due to the formation of rootlet tissueduring the germination period ice which removes material from the barleykernel. Upon drying the malt, the rootlets become Very fragile and areremoved by abrasion during subsequent handling. The rootlet lossgenerally amounts to 3 to 5% in conventional malting Operations.

It is generally considered that, for malt to be produced having suitablecharacteristics, the kernels be permitted or induced to grow rootletswithout hindrance during the germination period. De Clerck in A Textbookof Brewing, volume 1, page 156, states, At the end of this time, therootlets are generally l to ll/z times the length or" the corn, andobviously the shorter the rootlets, the lower will be the malting loss,but there may be insufficient modification. This view is supported byLeberle in Part I of The Technology of Malting, page 204, which whentranslated from the German indicates if no rootlets are formed nomodiication enzymatic production results. These are the views generallyaccepted in the malting industry and are supported by the commercialmethods of preparing malts since the germinating barley is turned ormoved only just enough to keep the grain and rootlets from entanglingand matting.

It has now been discovered, according to the present invention, thatcontrary to general concepts of good malting technique, increasedrecoveries of malt can be obtained by subjecting the steeped barley toconsiderable repetitions physical impact during the germination period.The amount and extent of the impact to which the germinating barley issubjected should be sufficient to at least significantly, and desirablymaterially, suppress growth of rootlets but without significantlyaltering or interfering, by such impact, with other growth andmodification processes, Broadly, impact and impingement as used hereinmeans to apply a shock force of at least 25() gm. cm. of kinetic energyto each kernel during the germination period, within the meaning of theinvention, it being understood that such value is calculated based onthe process in which impact alone is the means for suppressing rootletgrowth and no other means is used to suppress rootlet growth.

In the drawings which constitute a part of this application, and whichare described more fully in the examples:

FIGURE l illustrates a rotating cradle for experimental malting;

FIGURE 2 is a chart showing increased malt recovery, and reduction inrootlet growth, compared to rotation as percent of total malting time;

FIGURE 3 is a plan View of part of an apparatus for determining kernelimpaction;

FIGURE 4 is a side elevation of an apparatus for determining kernelimpaction, including the part of FIG- URE 3;

FIGURE 5 is a chart `showing reduction in rootlet growth per appliedimpact energy; and

FIGURE 6 is an enlarged sectional view showing a barley kernelpositioned in the apparatus.

Although the turning of germinating barley in conventional processesmight be considered a means of inducing a mild form of kernel impact orimpingement, it has for its primary purpose the prevention of matting ofthe germinating barley with the secondary purpose of maintaining theporosity of the barley bed so that air can be readily forced through thebed to achieve aeration. The turning operations of the conventionalmalting processes generally do not extend more than 1% of the totalgerminating time and, in addition, are so mild as to be insuicient tosuppress rootlet growth to any great extent. Indeed, in conventionalturning it is desired to avoid interfering materially with rootletgrowth.

Impact as used in this process is distinguished from the agitation ofnormal commercial malting practice in that it is ot such vigor andextent over such periods of 3 time that rootlet growth is significantlyreduced or, essentially, prevented.

Generally, in practicing the process of this invention, the subjectionof the germinating malt or barley to irnpact or impingement should befor at least of the total germinating time. However, the sequence ofphysical impacts can continue for the entire germination period withoutadverse results to the malt obtained. Continuance of the impact processfor greater than about 70- 80% of the total germination time is usuallynot Warranted because with lesser times of impingement or impact therecan be achieved most substantial suppression of rootlet growth. Indeed,if the impact process is sufliciently vigorous and frequent, there isoften no need to introduce such impact phase for greater than about 50%of the total germination period. Although it is desirable to at leastinduce this impingement for a minimum of 20% of the total germinationtime, it is advisable for economic reasons to increase the period ofinduced impact to comprise at least 30% of the total germination period.

Subjection of the germinating barley to physical impact can commence inthe period anywhere from steep out to about the end of the rst day ofgermination to obtain optimum results. The best results are obtainedwhen such induced impact is commenced immediately after steep out.Commencement of the impact process in the period of the second day ofgermination also gives improved recoveries of malt by suppression ofrootlet growth but the yields are not as high as those obtained whenimpact begins within the first day of germination. Commencement of theforced kernel impingement after the second day of germination has passedWill give some improvement in malt yield but the increased recoveriesare not very significant. Subjection to impact during the last, which isusually the fth, day of germination, is generally unnecessary to obtainthe increased recoveries of malt achieved by this process, but may beadvantageous in certain instances.

Even though it may be unnecessary to continue the impact process duringthe full germination period, it is usually advisable to perform it atleast intermittently during at least the first four days of germination.The periods of treatment can be of equal or unequal length and they canbe equally or unequally spaced during the germination period. Ingeneral, part of the total impact time should be used during each day ofgermination as well as during the day of steep out.

The impact action is advisably applied to inhibit rootlet formation byat least 331/3 and desirably by at least 50%, compared to the rootletformation of malt produced under otherwise identical conditions but withmild agitation used and limited to prevent matting and formation ofexcessive temperatures in the malting barley kernels without preventingrootlet' growth.

By the use of suitable kernel impingement to suppress rootlet growthduring the germination period, yields of malt can be increased up to 3to 4% higher than the yields obtained in some conventional maltingprocesses, with at least a 1% increase being sought.

In any process of malting without, or with only a minimum of, rootletsthere are several potential advantages. Compartment malting withcontinuous impact of the kernels upon each other and upon the walls,floor, and turning device should give a more even growth since thetemperature of the malt would be equalized from top to bottom of the boxby the continuous movement of the germinating barley. Green malt,without rootlets, occupies considerably less volume than when rootletsare present. There is thus a possibility of increasing the loading ofthe boxes by up to since formation of the bulky rootlet would besuppressed. Constant movement of the malt will keep it free and mucheasier to move as there can be no tendency to mat. The malt ows muchmore freely when the entangling rootlets are not present. This shouldreduce Wear on the malt transfer equipment.

It will readily appear to those skilled in the malting art andacquainted with machinery used in handling it and other grains thatsubjection of the germinating malt to impingement can be effected inmany ways and with widely different mechanisms to attain the resultsdisclosed and taught by this invention. It is only important, whatevermeans is used, that the energy of impact be of suicient magnitude andfor a sufficient time to reduce rootlet growth to the extent sought, butinsuicient to significantly etect adversely the physical structure ofthe kernels. Thus, the kernel impingement can be effected in beds withvigorous turning or by germinating the barley in rotating drums that canbe fixed with mixing or abrading blades.

The following examples are presented to illustrate the invention:

EXAMPLE l 350 g. samples of dry barley were weighed into one gallonbottles and steeped with appropriate Water changes at 55 F. At steepout, the moisture pickup of the sample was adjusted by addition ofcalculated amounts of water to give the desired malting moisture. Thebarley samples were germinated for five days at 62-64 F. undercontrolled conditions with three diifering degrees of intensity ofkernel impingement using the apparatus as shown in FIGURE l.

The apparatus as shown in FIGURE l comprises a rotating cradle whichholds the barley germinating bottles 10 and the humidier jar 11supported by pipes 13 and 14 and an identical third pipe not shown.These pipes are connected to supporting plates 15, each of whichcontains a shaft 16 and 16A which is supported by bearings to facilitaterotation. Pulley 17 is connected to drive means to rotate the cradle.Air enters the mechanism at 18 and after the flow is regulated bysuitable valves 19, it is fed to safety bottle 20 and from there throughhollow shaft 16A to flexible tube 21 into jar 11. l ar 11 contains glasswool and Water to regula-te the humidity of the air. The air then flowsthrough tube 22 to manifold pipe 14 which contains a plurality of valves23 to regulate the air flow by tubes 24 to the germinating bottles 10.Vents 25 permit exhaust air to leave the germinating bottles.

Rotation in such a manner as to cause the kernels to impinge on eachother or on other solid surfaces was continuous unless otherwise stated.The least .action was obtained by operating the malting apparatus togive a speed of rotation of 0.2 rpm. This is the minimum kernel motioncommensurate with the preparation of a `malt that is not severely mattedby entanglement of rootlets. In this `and all following examples thosemalts prepared at 0.2 rpm. are control malts. Without this minimumaction a usable product is not obtained. A rotation of 1.5 rpm. -wasconsidered to impart `an intermediate impact effect and high impingementwas obtained by placing 2 pieces of stainless steel rod one-half inch indiameter by six inches long in bottles that were rotating at 1.5 rpm.Other runs were made in which the energy of impingement was decreasedduring the germination period by the removal of the rods at the desiredtime and others in which rods were added to :the rotating bottles `atdefinite periods after steep out.

After germination, the green malts were weighed and dried on a pilotkiln according to the [following schedule: l2 hours at 120 F., 4 hoursat 140 F., 6 hours at 155 F., and 2 hours at 175 F. The weight of totaldried material was determined and the malts were cleaned to removerootlets and a small amount of husk. The recovery of clean malt wasdetermined by weighing the rootlets removed and subtracting this ligurefrom the total dry Weight.

5 The recovery of dried material from a series of malts having the samemalting moisture was very consistent with variations of les-s than onegram in total recovery from the 350 gram starting load of barley. Theresults are reported in Table l.

6 7 hours, `drained 15 hours, steeped 4 hours, and drained 2 hours, allat 55 F. The barley was then germinated 5 days at 62-64" F. withcontinuous subjection of 4the kernels to impact during germination fromsteep out as shown in foregoing Table 2. The green malt was kilned TABLE1 Dry Weight Rootlets Clean Percent Percent Rotation DescriptionRecovered, and Clean Malt, g. Rootlets Increase g. Out, g.

0.2 r.p.m 308. 7 13. 6 295. 1 4. 6 19, 0 1.5 r.p.m. 308. 7 10. 6 298. 13.6 2()- 2 1.5 r.p.m.-rods at steep out 308. 7 4. 4 304.3 1. 4 22 7 1.5r.p.m.-rods added at one day after steep out..- 308. 5 4. 2 304. 3 1. 422l 7 1.5 r.p.m.-rods ladded at two days after steep out. 308. 6 9. 6299. 0 3. 2 20l 5 0.2 r.p.m 309.0 15. 7 293. 3 5. 4 1g 3 1.5 r.p.m-.308. 8 12. 3 296. 5 4.1 19 6 1.5 r.p.m.-rods added at steep out andremoved 2 days after steep out.. 309. 1 8. 6 300. 5 2.9 21, 2 1,5r.p.m.rods added at steep out and removed 3 days after steep out 308. 96.3 302. 6 2.1 22, 0 1.5 r.p.m.rods added at steep out and removed 4days after steep out.. 309. 0 4. 0 304. 0 1. 6 22. 6

approximately 12 hours at 120 F., 4 hours at 140 F., 6 hours at 160 F.,and 2 hours at 170 F. The equip- 35 ment used `for `agitation was as inExample I.

Selected malts were analyzed by the Methods of Analysis of the AmericanSociety of Brewing Chemists, 6th edition, American Society of BrewingChemists, Madison, Wisconsin, 1958, and the results obtained are givenin the following table:

TABLE 2 Green Malt Rootlets Percent Sample Rotation 1 Moisture, CleanMalt Number Description Percent Malt, g. Increase Grams Percent 1A=0.2r.p.n1. rotation. B=1.5 r.p.m. C=1.5 r.p.m. and 2 rods.

TABLE 2A Sample Numbers 3 4 5 6 7 8 Growth Acrosp 0% Length of Ker 1 0 01 0 1 4% Length of Kern 1 1 1 1 1 1 1 g% Length of Kernel 12 4 2 4 1 1-l Length of Kerne 85 91 95 93 89 74 Over 1 Length of Korn 1 4 2 1 9 23Assortment:

On 764 Mesh Screen 9.6 19. 9 30. 0 11. 1 26. 9 38.3 On 964 Mesh Screen69. 2 71. 0 62. 6 72. 9 64. 8 55. 3 On %4 Mesh Screen.- 21.0 8. 9 7. 115. 7 8.0 6. 0 Thru %4 Mesh Screen- 0.2 0. 2 0. 3 0. 3 0.3 0. 4 Moisture(Percent) 4.1 4. 1 4. 1 4.1 4.0 4. 1 Dry Extract (Percent) 76. 3 75. 775. 3 76. 1 75.8 75.0 Color L) 1. 80 1.83 1. 81 2.04 1. 90 1. 84Diastatic Power 129 116. 111 120 119 111 Alpha-amylase (20 Units 48.841. 7 35.1 50. 7 44. 5 36. 5 Total Protein (Percent) 11.07 10.60 9. 9110.98 10. 23 11. 39 Soluble Protein (Percent) 4.85 4. 42 4. 44 5. 11 4.83 4. 44 Wort pH 6. 07 6. 03 6. 02 5. 97 6. 07 6. 07

7 e The eltect of moisture on respiration loss is illustrated The pointson FGURE 2 of the attached drawing are in Table 2, where at about 43%moisture the total rethe average of the three rod-containing samplesprepared COVefY Was 3106 g at abOUt 445% moisture the Ieby each rotationschedule. As the time under impinge- COVefY WHS 309-8 g, and at 46%moisture the feeOVefY ment was increased from about 8 to 50 percent ofthe We? .309- g .This indicates that eddttton'fl enzyme-tte 5 time, theincrease in malt recovery was more than 2% but aettvtty eeeuttmg at thehtgh motstute level tesptted further increase in treatment time resultedin an addiabout one and one-half grams more carbohydrate than tionalincrease of only about 0.3%

from the low moisture level malt.

Also, it Should be noted in the Same table that the The increase 1n maltrecovery almost exactly balances amount of rootlet in relativelyundisturbed malt increases with increasing malting moisture, from 12.4g. at 43% 0 that those components that would normally be used in themoisture to 15.2 g. at 46% moisture While the most formation of iootletare being retained in the kernel and vigorous degree of mpingement gavecomparable Weight that the action of the forced kernel impact 1s toprevent of rootlets from the three moisture levels of from 3.5 to thetofmatton ot Toottet tether than a removal of toot' 3.9 g. On a Weightbasis, the increase in yield obtained l5 let after it has been fOrIled.by increasing the degree of impingement from low to high amounted tomore than grams of cleaned malt from a normal recovery of 290 to 300grams. This is EXAMPLE 1V an increase of greater than 3.3% in maltrecovery. EXAMPLE III Y 35o g- Samples 0f oKndl'ed barley Were steepedand The effectiveness of impact in preventing rootlet formagefmlrlatedat 63 to 65 F. for `1Ve days. Seleeted Samljles tion, pilot germination(560 g. barley) of commercially were germinated in bottles as in ExampleI with and Withsteeped barley was Compared with commercial gel-minaoutthe presence of two 1/2 by 6 stainless steel rods to increase the impacteilect on the sample. The samples were rotated at 1.5 revolutions perminute and the rotation was interrupted for differing length of timeeach day throughout the germination period. The following schedules weremaintained for rotation induced impact tion (2500 bushels) of the samebarley. The commercial germination wasv performed in a customary largecompartment with the normal ow of humidiied air through the perforatedbottom and then through the malt. As customary, the malt was turned andmixed about every 8 during germination hours with traveling verticalhelices to prevent excessive TABLE 3 rootlet formation and matting.

For the pilot study the apparatus of FIGURE 1 was I-Iours Hours NotPercent e i Schedule Rotated Rotated Time Under us d and a comparison'.vas made between periodic turn Rotation ing at 0.2 rpm., continuousturning at 1.5 r.p.m., and

continuous turning at 1.5 r.p.m. with 6 aluminum rods the decrease inrootlet formation. This would indicateY 24 o 160 (1/2'l by 6) includedin the jar contents. It should be 1g g?) noted that the 0.2 rpm.periodic turning permitted excesg 3g sive rootlet formation with astrong tendency to mat; theV 40 continuous 1.5 r.p.n1. turning permittedcontrolled root- The malts were kilned asln Example 1 The following letformation. Data follow for percent rootlets formed Table 3A shows therecoveries of malt and rootlets for and feeOVered after kilmng, fOr maltalpha-amylase activthe various schedules. ity, and for kernelmodification:

TABLE 3A Rods in Dry Sub- Clean Clean Percent Percent Schedule Samplestance, Out, Malt, Clean Increase Grams Gra-ms Grams Out 315. i 10.3304. s 3. 4 22. 9 316. 9 4. 6 312.3 1. 5 25.9 316. 4 4. 9 311.5 1. 625.6 316. 6 4. 9 311.7 1. 6 25.7 316. 3 9. 9 306. 4 3. 2 23. 6 316. 1 5.0 311. 1 1. 6 25.3 316. 4 4. 8 31-1. 6 1. 5 25.7 317. 0 5.1 311.9 1. 625. 8 317. 7 10. 1 307. 6 3. 3 24. 0 316. 4 5. 7 310. 7 1. s 25.3 316. 45. 9 310. 5 1. 6 25. 2 316. 8 5. 2 311. 6 1. 7 25.6 316. 7 11.2 305. 53. 7 23. 2 316. 0 7. 4 30s. 6 2. 4 24. 0 316. 5 6. 9 309. 6 2. 2 24. 8316. 4 7. 2 309. 2 2. 3 24. 7 315. 8 14.1 301. 7 4. 7 21. 7 316. 0 11.3304. 7 3. 7 22. 0 315. 6 11. 3 304. 3 3. 7 22.7 315. 6 11.6 304. 0 3. 822. 6

TABLE 4 Modification1 Germination Rotation Rootlets, Alphacoarse-finepercent amylase diicrenco units Commercial Normal, periodic 3. 40 49 2 2Pilot 0.2 rpm., periodic 7.14 58 l 8 1.5 rpm., continuous 2. 71 48 1 91.5 pru., eontinouus with 0.49 28 1 9 lO S.

1 The diterence in wort extract obtained by comparing the mashing of acoarsely ground malt and tlic'mashing of a finely ground malt isuniversally considered as n measure ol kernel softening ormodificatiou"-the lower the dillerence between the two values the betterthe modification.

lt is apparent from Table 4 that simple more rapid turning of jars, evencontinuously at 1.5 rpm., permitted reduced rootlet production comparedto normally stirred commercial malt, with similar alpha-amylase andmodilication values. However, the introduction of rods into the jarduring rotation introduced an impingement process with the applicationof increased kinetic energy to the kernels whereby rootlet production ofan entirely different order resulted. In fact, almost no rootletproduction was visible, the 0.49% rootlet loss being composedsubstantially of liaked-oi chalf resulting from processing of the maltthrough germination, kilning, and cleaning. The iinished malt hadadequate alpha-amylase activity, and modification even better than thatachieved pilot-wise without the impingement process or by commercialprocessing.

EXAMPLE V Quantitative measurement of the impact required to preventrootlet growth The data of Table 3B of Example lII, show clearly that,for this barley, the rotation of the malting jars, Without rods toactivate the impingement of kernels on each other and on other solidsurfaces achieved little, if any, reduction of rootlet growth withincreasing percentage of rotation time over about 33%. However, use ofthe energy-inducing rods caused progressive reduction in rootlet losswith introduction of the rods up to some 67% of the germination time. Anincrease of the rod impingement action up to 100% of the germinationtime induced no further reduction in rootlet loss, with a plateauapparently being reached, in this instance, at about 1.5 to 1.6% rootletloss. As in previous experiments, much of the rootlet loss with terminalimpact control consisted of chat and particles, other than rootlets,abraded oli in process.

To determine the minimum amount of impact energy required to preventrootlet growth, an energy level above which no further reduction inrootlet growth would occur, on an individual kernel, equipment wasdesigned to subject the embryo ends of individual germinating barleykernels to a controlled and measured impact throughout germination. Theseries of impacts, or impingements, were of timed frequency and degreefor a 5-day germination period, from just after steepout of the barleyto just before kilning. An intermediate size of barley was used with anaverage individual kernel weight, after steeping to 45% moisturecontent, of 0.055 g.

The equipment is shown in FIG. 3 (top View of kernel holding plate) andFIG. 4 (side View of the complete apparatus). In the figures, the samenumbers are used to identify the same parts or elements. A plate ofclear plastic which is 17 cm. x 18.4 cm. by 1.2 cm. thick is providedwith twenty rows of slightly conical holes 31 with twenty holes to therow to give four hundred holes in all. The holes are smaller at thebottom than at the top and are of sufiicient bore so each can contain asingle kernel 32 of steeped, or germinating, barley without binding withthe germ end 37 down. The hole is approximately 5 mm. dia. at the topand approximately 3 mm. dia. at the bottom. The germ end 37 of thekernels protrudes on the average about 1 mm. below the bottom of plate30. FIG. 6 shows a kernel in one such hole in sectional view. A screen53 is aiixed on the upper surface of plate 30 to prevent the kernelsfrom popping out ot the holes upon impact with the lower, solid plate34. Thus the kernels are not crushed against the lower plate 34 byfalling kernel-holding plate 30 since the kernels are `free within theircontaining holes.

Plastic plate 30 is hinged to solid plate 34, of the same size as plate30, at point 3S in such a fashion that at the line of the lirst row oftwenty holes 36 the embryo end of the germinating kernels, such as 37 inFIGS. 4 and 6,

are in constant, and static, contact with the lower plate 34. To theupper plate 30 at point 33 is atlixed arm 3S. This arm is suspended by ahook 46 to an adjustable connecting rod 39 aflixed to a horizontal arm40. Arm 40 is hinged at point 4l to vertical support 42. Arm 40 isactivated by motor driven cam 43 so as to give a Vertical drop of plate30 of 1 cm. at point 44, the edge farthest removed from the hinge 35.

The two plate device for holding the germinating kernels 30 andproviding an unyielding impact surface on plate 34 is completelycontained within a humidilication chamber 45 such that the steeped-outkernels maintain 45% moisture and be under favorable conditions forgrowth and modification.

The distance of fall of each row of kernels could be measured, from 0cm. at the hinge end, row 1 of FIG- URE 3, to 0.840 cm. at the rowfarthest removed from the hinge end row 20. The number of impacts perminute was regulated by adjusting the velocity of rotation of the cam 45of FIGURE 4, by means of a variable speed motor and belt drive (notShown). By measuring the speed of rotation of cam 43, the distance ofdrop of each row of kernels, the weight of eaoh kernel, and the distanceof travel of arm 40 as it dropped the 1 cm. distance on the cam it waspossible to calculate the velocity of kernel fall and the energygenerated by the kernel on impact with the lower plate 34 in gm. cm. perdrop, per kernel.

Calculations required are as follows:

at (l) Te-'Djr where where:

A=acceleration of falling kernel. S=space of drop (distance passedthrough by falling kernel). T=time required for drop (from Equation l).

(3) V=\/2AS where:

V=velocity of falling kernel. A=acceleration (from Equation 2). S=spaceof drop (distance of fall of kernel).

(4) KE 2g where KE=kinetic energy of kernel impact against plate 34 ofFIGURE 4, expressed in grn. cm.

W=weight of barley kernel.

V=velocity or' fall (from Equation 3).

g=gravity constant (980).

In the experiment of this example there were 108,000 drops during theS-day germination period. For this eX- periment, with intermediate sizekernels at 45% steepout moisture, the impact energy per kernel over the5- day period was measured for section-rows 2 through 5, section-rows 6through 9, section-rows 10 through 13, and section-rows 14 through 17.By visual inspection rootlet growth decreased progressively through theiirst 13 rows to reach essentially no growth at row 1.4 and 1 tcontinued absence of growth through rows 15, 16 and 17. At the end ofthe days the kernels were removed from the apparatus, the rootletscarefully removed from each kernel by scissors, and the kernels androotlets dried (kilned) and weighed. Alpha-amylase was determined on thekernels to evaluate malting response. The data obtained is in Table 5.

TABLE 5 Alpha-amylase Average 5-day Rootlet1 activity Rows impact energyrecovery,

per kernel, percent gm. om. Units/ Units/- kernel gram 1 It should benoted that the rootlet loss in this example is less for active growth,rows 25, than in some of thc previous examples, due to the conditions ofgrowth and the manner'of rootlet removal.

The rootlet growth, and recovery, for each row in the 14-17 row area, byobservation, was uniform and minimal, limited to incipient stubs that,while removed by the scissors and measured, could just `as readily becharacterized as not being due to true rootlet growth and elongation.Beginning then with an impact energy of 2793 gm. cm. per kernel per 5days (row 14) through 4389 gm. cm. per kernel per 5 days (row 17) nofurther reduction in rootlets occurred and yet the alpha-amylase`activity for the 4r0w area showed a value sufficiently high, 29 units,to indicate malting had been accomplished without rootlet growth.Accordingly, it becomes obvious that an impact energy of somewhat over2500 gm. cm. per kernel per 5 Adays may be required to stop rootletgrowth completely with a barley individual kernel weight ofapproximately 0.055 gram.

The above deals with malting at 45% moisture. 1t is feasible to malt atlower moistures, say as low as 40%, and at higher moistures, say as highas 50%. At 50% moisture proportionally less drops per minute would berequired for the same impact energy, and at 40%Y malting moisture,proportionally more. Further, very small berries may be malted,requiring many impact drops per minute, and very large berries requiringmuch fewer impingements per minute.

The ultimate objective of theV invention, essential elimination ofrootlets with retention of malt properties, was realized by a totalcumulative physical impact or impingement energy of ysome 2800 gm. cm.per kernel. Very substantial reduction of rootlets, to approximatelyonethird of normal was achieved by about 1800 gm. cm. per kernel.

EXAMPLE v1 rl`his experiment is a repeat of Example V using a similarintermediate size of Kindred barley, steeped to 45% moisture, placed inthe apparatus described in FIGURES 3 and 4 and germinated undercontrolled temperature of 60-62" F. and high humidity for 5 days, beforeremoval' of the kernels from plate l0, excising of the rootlets, anddrying for Weight and analysis. In this case, however, instead ofmeasuring average rootlet loss and enzyme activity for 4-row blocks ofkernels, data were obtained for the kernels of individual rows 2 through17 of plate 10.

The data are given below in tabular form and are presented graphicallyin FIGURE 5.

TABLE 6 Alpha-amylase Total 5-day `Rootlet activity Row impact energyrecovery,

per kernel, percent i gm. om. Units] Unrts/ kernel gm.

11. 3 2. 92 1.32 43 54. 9 2. 87 1. 08 35 119 2.81 225 1. 94 1. 56 47361 1. 82 1. 43 43 556 1. 52 l. 52 45 791 1. 49 1. 40 44 1, 063 1, 1297Y 29 1, 353 .88 1. U6 30 l, 740 95 1. 26 42 2, 014 93 29 2, 395 75 8526 2, 793 86 92 31 3, 318 31 3,807 35 1. 06 33 4, 389 35 90 29 Visualobservation of the kernels at the end of 5 days germination indicatedthat there was full rootlet growth in rows 2 to 4 with the leastimpact., Rootlet growth was progressively less with increased impactuntil, starting with row l5, there was essentially no growth other thanthe stubby, elongated embryo cap.

The alpha-amylase data of the table show that essentially there was nosignificant change in the activity from row 9 through row 17 even thoughrootlet growth was reduced to minimal levels in the row l5 to 17 area.The number of kernels, and weight of malt, was inadequate to permitquantitative measurement of kernel modication.

-However, while crushing the kernels for alpha-amylase extraction it wasobserved that they were not hard but soft, easy to crush, andwell-modified through the kernels of row 17. Y

Graphical presentation of the data, as given in FIG- URE 5, isillustrative of the impact phenomenon. A slight stunting of the rootletsoccurs in the 0 to 200V gm. cm. range. This is similar to commercialagitation. How-4 ever, by increasing the impact energy to the range of,500v tok 1500 gm. cm. the rootlet production can be progressivelyreduced to about one-half and down to about onethird of normal. Then, inthe impact energy range of some 1500 to 2800 gm. cm., the rootlet lossreaches itsv rst leveling off and holds quite constant with a maltalpha-amylase activity lower than normal but entirely acceptable.

With impact energy of above some 2800 gm. cm. per kernel another sharpdrop in rootlet growth occurs, down to the minimal level of some 0.3%,to remain uniform through some 4500 gm. cm. This occurs without any dropin malt alpha-amylase activity.

It becomes obvious that two signicant rootlet control phenomena arepresent, a reduction to about 1/s of normal by impact energies in therange 1200 to 2800 gm. cm. and a further reduction to essentialelimination with impact energies above some 2800 gm. gm. total impactper kernel throughout the malting period.

The evidence from previous examples indicates that this total impact orimpingement energy does not need to be applied evenly and continuouslythroughout germination but may be intermittent, especially to achievethe two-thirds level-of reduction in rootlet loss associated with thei'irst phenomenon in impact malting.

Various changes and modifications of the invention can be made and, tothe extent that such variations incorporate the spirit of thisinvention, they are intended to be. included within the scope of theappended claims.

What is claimed is:

1. The process of increasing malt recovery which comf prises subjectingsteeped barley, commencing within one day after steep out, to enforceimpact during at least 20% of the total germination time with the impacteffect being applied at a rate and to an extent sufcient to materiallyt3 suppress growth of rootlets without significantly altering by suchimpact other growth and modilication processes that take place duringthe conversion of barley to malt.

2. The process of claim 1 in which the total impact time is not morethan 75% of the total germination time.

3. The process of increasing malt recovery which comprises subjectinggerminating steeped barley, commencing within one day after steep out,to enforced physical impact during at least of the total germinationtime with the impact process being applied at a rate and to an extentsutiicient to materially suppress growth of rootlets by at least 50% ofthe growth obtained with normal stirring and thereby increase the maltrecovery by at least 2% without significantly altering, by such impact,other growth and modication processes that take place during theconversion of barley to malt.

4. The process of increasing malt recovery which comprises subjectinggerminating steeped barley, commencing within one day after steep out,to enforced impact during at least 20% of the total germination timewith the impact process being applied at a rate and to an extentsufcient to materially suppress growth of rootlets by at least 50% ofthe growth obtained with normal stirring and thereby increase the maltrecovery by at least 2% without signicantly altering, by such impact,other growth and modification processes that take place during theconversion of barley to malt.

5. The process of increasing malt recovery by at least 2% whichcomprises subjecting steeped barley, commencing within one day aftersteep out, to a physical impact ot the kernels during `at least 20% ofthe total germination time with the impact being applied at a rate andto an extent suflicient to inhibit rootlet formation withoutsigniicantly altering, by such impact, other growth and modificationprocesses that take place during the conversion -of barley to malt, withthe rootlet inhibition being not less than about compared to the rootletformation of malt produced under otherwise identical conditions but withagitation limited to prevent matting and localized excessivetemperatures in the malting barley kernels without preventing rootletgrowth.

6. The process of increasing malt recovery by at least 2% whichcomprises subjecting steeped barley, commencing within one day aftersteep out, to a physical impact which subjects the kernels tosubstantial impact pressure during about 20% to about 80% of the totalgermination time with the impact being applied at a rate and to anextent sufcient to inhibit rootlet formation without signincantlyaltering, by such impact, other growth and modiication processes thattake place during the conversion of barley to malt, with the rootletinhibition being not less than about compared to the rootlet formationof malt produced under otherwise identical conditions but with mildagitation limited t0 prevent matting and formation of excessivetemperatures in the malting barley kernels without preventing orinterfering with rootlet growth.

7. The process of increasing malt recovery which comprises subjectingsteeped barley, commencing within one day after steep out, to physicalimpact energy of at least 50G gm. cm. per kernel during the germinationperiod with the impact energy being applied at a rate and to an extentsuicient to materially suppress growth of rootlets without signicantlyaltering by such impact other growth and modication processes that takeplace during the conversion of barley to malt.

8. The process of claim 7 in which at least 1000 gm. cm. of physicalimpact energy is applied per kernel during the germination period.

9. The process of claim 7 in which from about 1500 to 5000 gm. cm. ofphysical impact energy is applied per v kernel during the germinationperiod.

10. The process of reducing the loss due to rootlets to not more than 2%in the malting of barley which comprises subjecting steeped barley,commencing within one day after steep out, to enforced impact during atleast 20% of the total germination time with the physical impact energybeing at least 500 gm. cm.

11. The process of claim 10 in which the rootlet loss is not more than1%.

12. The process of increasing malt recovery which comprises subjectingsteeped barley, commencing within one day after steep, to enforcedimpact during at least 20% of the total germination time to suppressrootlet growth, said impact force reducing any loss due to rootletgrowth to less than 2%.

13. The process of claim 12 in which the impact is applied to reduceloss due to rootlet growth to less than about 1%.

References Cited in the tile of this patent UNITED STATES PATENTS1,117,323 Chichester Nov. 17, 1914 2,901,401 Grimm et al. Aug. 25, 19592,947,667 Komm Aug. 2, 1960 2,960,409 Macey et al Nov. 15, 19603,014,847 Kneen et al Dec. 26, 1961 UNITED STATES PATENT @Tries CETHQATE @E C@ E611 Patent No. 3,174,909 March 23, 1965 Lawrence D.Beckord et a1 1t is'hereby certified that error appears in the abovenumbered patent requiring correction and that the said Letters Patentshould read as corrected below.

Column Z, 1ine 17, after "modification" insert or column 7, 1ine Z7, for"length" read 1engths column 9, line 54, for "17" read 17.5 column 10,line 20, for "45" read 43 column 12, line 73, for "enforce" readenforced column 14, 1ine 54, after "steep" insert Signed and sealed this27th day of Ju1y 1965.

(SEAL) Attest;

ERNEST W.. SWIDER EDWARD' J. BRENNER Attestlng Offlcer Commissioner ofPatents

1. THE PROCESS OF INCREASING MALT RECOVERY WHICH COMPRISES SUBJECTINGSTEEPED BARLEY, COMMENCING WITHIN ONE DAY AFTER STEEP OUT, TO ENFORCEIMPACT DURING AT LEAST 20% OF THE TOTAL GERMINATION TIME WITH THE IMPACTEFFECT BEING APPLIED AT A RATE AND TO AN EXTENT SUFFICIENT TO MATERIALLYSUPPRESS GROWTH OF ROOTLETS WITHOU SIGNIFICANTLY ALTERING BY SUCH IMPACTOTHER GROWTH AND MODIFICATION PROCESSES THAT TAKE PLACE DURING THECONVERSION OF BARLEY TO MALT.